Beautiful Compounds: How Birds’ Feathers Get Their Color

John Emmet Andrews, an undergraduate working with Dr. Alex Badyaev (who also is the photographer for this year’s conference poster), will be one of many student researchers presenting a poster at the 27th Annual UBRP Conference!

Photo: House Finch by John Benson

One of the many fascinating characteristics of birds are their beautiful colors, but how do birds make their colored feathers? That is the question which researchers in the Badyaev lab at the University of Arizona are currently exploring. Led by Dr. Alex Badyaev, UA professor of Ecology and Evolutionary Biology, his team looks specifically at the compounds inside of feathers which give them their different colors.

“It’s very cool!” said undergraduate researcher Emmet Andrews. “Many of the wonderful colors that we see in bird feathers, such as reds and oranges, are actually carotenoid compounds found in the feathers. What’s really interesting though, is that for a bird to make a carotenoid, they first have to eat a carotenoid!” What Mr. Andrews is describing is part of the process by which bird feathers become colorful. Birds cannot actually create carotenoid compounds by themselves, this means that they have to first eat a carotenoid which can be found in plants and fungi, and then turn them into the carotenoids they put in their feathers.

“However” Emmet continues “creating the carotenoid a bird needs from the carotenoid the bird has can be incredibly complex.” Birds have metabolic networks inside them which are like tiny factories, taking the raw materials of carotenoids the bird ate, and producing the final product of the necessary compound. What makes this complex is that networks are different than assembly lines. Imagine if in this factory, instead of having a single assembly line, it had twenty. All crossing each other and going forwards and backwards, all dependent on which stage they were in, or what other materials are present at that time. That is more like what the network looks like.

This sounds really complex, so how are they studying these big networks? The answer is one species at a time. Right now the Badyaev lab has a focus on a species of house finch which is native to Arizona, (Haemorhous mexicanus). The team at the Badyaev lab has already figured out the paths of this species network, but now they are looking at how they function under different conditions. Researchers in the lab have collected feathers from Haemorhous mexicanus in southern Arizona, and also in members of the species who have moved all the way up to Montana. Erin Morrison, a PhD student in the Badyaev lab, commented on her research, saying “We are trying to determine how the pigment deposited in feathers changes as the feather ages, this is important for understanding how mechanisms of feather coloration are related to different life history strategies, particularly for breeding and mate choice.”

Research in this field of biology is still ongoing, but those who are doing the leg work are optimistic about what they can learn from studying these feathers. Research conducted by scientists such as Erin Morrison can lend us stores of information about the lives of birds, just by looking at their feathers, and I for one am excited to see what the Badyaev lab learns about our flying friends.